A wireless communication system has been rapidly developed. Particularly, as a result of various demands of users, a system supporting a high speed and large capacity data service is necessary. In order to meet traffic demands of wireless data, which has continuously increased, wireless communication systems supporting a higher data transmission rate have been developed. A next generation wireless communication system seeks to develop a technology that mainly improves a spectral efficiency to increase a data transmission rate. However, meeting the traffic demands of wireless data that have increased heavily through improvement of the spectral efficiency alone is difficult.
One of methods to solve the above identified problems uses a very wide frequency band. A frequency band used in a mobile communication cellular system according to the related art generally corresponds to 10 GHz or lower, thereby having a difficulty in securing the wide frequency band. Accordingly, securing a broadband frequency in a higher frequency band is required. In order to secure the wide frequency band such as a super high frequency, a millimeter (mm) wave system may be introduced. The millimeter wave system considers a beamforming technology in order to mitigate a propagation path loss according to a frequency characteristic and increase a delivery distance of a radio wave transmission distance.
However, efficiently supporting a large capacity service of the user located in a cell boundary area and guaranteeing a stable link by a channel characteristic of the millimeter wave band using solely beamforming technology is difficult. For example, when only one communication link (Tx-Rx beam pair) exists, a situation in which communication is disconnected by unexpected obstacles may occur. As a technology to solve the above problems, a communication system that provides a service to one Mobile Station (MS) through cooperation between a plurality of Base Stations (BSs). In other words, a communication system that provides a service to one MS using cooperative communication between BSs has been researched.
In forming a cooperative BS group, methods that mainly mitigate interference or increase a received signal to interference plus noise ratio may be considered. However, in the millimeter wave beamforming system, reliability of a link is a very important consideration, and accordingly, a method of forming a BS group taking account of the reliability is needed.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.